Many electrical and electronic devices generate radio frequency or other electromagnetic radiation during operation. It is often desirable to shield such devices with an electrically conductive material to prevent consequent electromagnetic interference (EMI) with other devices. Traditionally, electrically conductive materials have been restricted to metals, but polymeric materials frequently offer superior properties (such as low weight and corrosion resistance) and greater design flexibility than metals and it would thus be desirable in many cases to make parts for such applications from electrically conductive polymer resins.
JP H06-240049 A discloses a thermoplastic resin composition comprising 3 to 30 weight percent carbon fiber having a diameter of 1-6 μm and 0 to 20 weight percent carbon black.
JP H09-87417 A discloses a conductive thin molded article having excellent conductivity and sufficient rigidity for use as a casing material, even when molded into articles having a thickness of 2 mm or less. The article comprises a conductive composite material in which conductive fibers and carbon black are compounded with a matrix resin consisting primarily of a thermoplastic resin. The average length of conductive fibers in the molded article is 0.5 mm or more.
WO 2003/029352 and U.S. Pat. No. 6,995,205 B2 disclose a highly thermally conductive resin composition having a high thermal conductivity and good moldability. The composition comprises at least 40 volume percent of a matrix resin, 10-55 volume percent of a thermally conductive filler, and a metal alloy having a melting of 500° C. or less that binds the thermally conductive filler particles to each other. The volume ratio of the metal alloy and thermally conductive filler ranges from 1:30 to 3:1.
JP H06-196884 A discloses resin compositions comprising a filler (such as a metal, alloy, or ceramic) having a high thermal conductivity dispersed in a matrix resin. The composition further comprises a low-melting-point metal alloy. When an article comprising the composition is heated at a temperature at which the low-melting-point metal alloy is completely melted, the alloy is fused with the filler particles, cross-linking them.